The present invention relates to magnetic writers. More particularly, the present invention relates to an electroplated multilayer high moment structure for use in a magnetic writer.
Magnetic heads typically include both a write element and a read element. The read element includes a magnetoresistive (MR) or giant magnetoresistive (GMR) element for reading information from a recording layer of a recording medium (e.g., a magnetic disc). The write element is configured to generate magnetic fields that align magnetic moments of the recording layer to represent bits of data.
Write elements can include two poles, each of which have a pole tip. The pole tips are separated by a gap layer at an air-bearing surface (ABS), which faces the recording medium. A conductive coil surrounds a section of a magnetic circuit formed by the two poles. Current signals in the coil induce magnetic signals in the two poles, which are used to write data to the recording medium. The write element may alternatively include a single pole for writing data to the recording medium.
In perpendicular recording, magnetic signals are conducted through a writing pole in a manner that orients the magnetic moments of the recording medium perpendicularly to the surface of the recording medium. The amount of data that can be recorded in a given area (i.e., the areal density) can be improved by reducing the surface area of the pole tip of the writing pole and by increasing the linear density and the frequency at which data is recorded.
The writing pole may be formed by sputtering a single layer of high magnetic moment materials with a high saturation flux density. However, sputtered high magnetic moment films exhibit high coercivity, poor anisotropy, and high intrinsic stress. This causes high remnant magnetization in the writing pole, which can lead to on-track erasure (OTE) of data. The remnant fields that cause OTE, which become more significant with increasing areal densities, may be due to ferromagnetic coupling within the writing pole. One approach to resolving this is to form the writing pole by sputtering laminated layers of magnetic and nonmagnetic materials to prevent exchange coupling between the layers. However, additional processing, such as milling, is needed to define the shape of the sputtered writing pole.